An optical transmitter may emit light that is directed toward an object. For example, in a gesture recognition system, the optical transmitter may transmit near infrared light toward a user, and the near-infrared light may be reflected off the user toward an optical receiver. In this case, the optical receiver may capture information regarding the near-infrared light, and the information may be used to identify a gesture being performed by the user. For example, a device may use the information to generate a three dimensional representation of the user, and to identify the gesture being performed by the user based on the three dimensional representation.
In another example, information regarding the near-infrared light may be used to recognize an identity of the user, a characteristic of the user (e.g., a height, a weight, a pulse, a blood oxygenation, etc.), a characteristic of another type of target (e.g., a distance to an object, a size of the object, a shape of the object, a spectroscopic signature of the object, etc.), and/or the like. However, during transmission of the near-infrared light toward the user or object and/or during reflection from the user or object toward the optical receiver, ambient light may interfere with the near-infrared light. Thus, the optical receiver may be optically coupled to an optical filter, such as a bandpass filter, to filter ambient light and to allow near-infrared light to pass through toward the optical receiver. Additionally, or alternatively, when performing sensing of multiple wavelengths of light, a filter may be provided to ensure that each wavelength of light, of the multiple wavelengths of light, is directed to a different sensor.
A multispectral sensor device, which may be an optical receiver, may be utilized to capture information about the multiple wavelengths of light. The multispectral sensor device may include a set of sensor elements (e.g., optical sensors, spectral sensors, and/or image sensors) that capture the information and are coupled to a multispectral filter. For example, an array of sensor elements may be utilized to capture information relating to multiple frequencies, and the multispectral filter may direct, to each sensor element, light associated with a different frequency. In some cases, a single filter may be disposed to cover each sensor element of the sensor element array, and may form a set of channels for the sensor element array.